Abstract
Protein biosynthesis depends on the availability of ribosomes, which in turn relies on ribosomal RNA production. In eukaryotes, this process is carried out by RNA polymerase I (Pol I), a 14-subunit enzyme, the activity of which is a major determinant of cell growth. Here we present the crystal structure of Pol I from Saccharomyces cerevisiae at 3.0 Å resolution. The Pol I structure shows a compact core with a wide DNA-binding cleft and a tightly anchored stalk. An extended loop mimics the DNA backbone in the cleft and may be involved in regulating Pol I transcription. Subunit A12.2 extends from the A190 jaw to the active site and inserts a transcription elongation factor TFIIS-like zinc ribbon into the nucleotide triphosphate entry pore, providing insight into the role of A12.2 in RNA cleavage and Pol I insensitivity to α-amanitin. The A49-A34.5 heterodimer embraces subunit A135 through extended arms, thereby contacting and potentially regulating subunit A12.2.
Original language | English |
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Journal | Nature |
Volume | 502 |
Issue number | 7473 |
Pages (from-to) | 644-9 |
Number of pages | 6 |
ISSN | 0028-0836 |
DOIs | |
Publication status | Published - 2013 |
Externally published | Yes |
Keywords
- Catalytic Domain
- Crystallography, X-Ray
- DNA/chemistry
- Models, Molecular
- Peptide Chain Elongation, Translational
- Protein Binding
- Protein Conformation
- Protein Multimerization
- Protein Subunits/chemistry
- RNA Polymerase I/chemistry
- RNA Polymerase II/chemistry
- RNA Polymerase III/chemistry
- Saccharomyces cerevisiae/enzymology
- Transcription, Genetic